---

Hi guys!

I am the proud new owner of an older 50 horse 4 cylinder outboard and I was wondering if anyone has one? Im looking for a manual and I cant seem to find a good one online...any help here? Thanks!

The motor came with a 15 foot steury tri-hull and trailer, im building a motor stand so I can take the motor off and get rid of that boat. Motor is going on a 13 foot 1969 whaler ive been restoring. Any ideas for motor stands? I feel like a hoarder with two boats in my yard.

Thanks for the help and advice as always!
Mike

---

If the link works, this may help you out:

https://onedrive.live.com/view.aspx?c...&wdo=1

If you need a good source for replacement engine decals, I recommend this fellow:

http://www.nymarine.ca/index.htmlindex.html

---

Very nice running engine, I've had a number of them through the years and currently have a '95 4 cylinder 40 I purchased new with oil injection and power trim. Mercury produced the 44 cu in 4 cylinder from the mid '50's to '98. If you have a very rare 15" short shaft it will bolt to your '69 short transom, otherwise you are going to need to increase the transom height or mount the engine on a jack plate to get the engine to the correct ride height. If this engine has been sitting for some time, I recommend rebuilding the carburetors and fuel pumps, replacing all of the fuel hoses, filter and install a new water pump impeller. These engines had an impeller style that put a lot of pre-load on the impeller vanes that would cause the rubber vanes to set in a semi-closed position after sitting for as little as a year and not pump water, additionally the rubber vanes can break off and lodge in the powerhead base, forcing you to remove the powerhead and find the broken piece or it will obstruct water flow and cause overheating. Also change the gear oil in the lower unit since you're doing the water pump anyway. For the DIY the parts to do all of this will run about $125 and worth every penny. Plus you have a maintenance baseline. One quirk about the lower unit on this engine is never shift it into reverse without spinning the propeller or having the engine running or you can break the shift cam in the lower unit and you will need to completely disassemble the lower unit to replace it. I've collected old Mercs for years so I have some experience dealing with their quirks. All in all if this engine has had a good life and been maintained it will outlast you! This is one of the best engines Mercury ever made.

---

I had a New 1976 Mercury 50 hp for my 1969 13' Whaler. Ran it for several years in salt water and liked it so much I bought a new one to replace it before that one died. I kept it in the kitchen in the crate for a few years until I needed it. It was a rare one as it was manual start only and a 15" shaft. Good luck.

---

Thank you for all the info! Ive got to find someone with a table saw to make those damn 8 degree cuts for the motor stand...maybe I can just build it upright with my circular saw?

Thank you for all the motor info, it is unfortunately a 20" shaft and I havent decided if I will just build up the transom or get a jack plate...thoughts on this? Im leaning towards the jack plate incase I go to sell and someone wants to keep the boat as original as possible. Was IMPOSSIBLE to find a 15" shaft motor. When I purchased I made sure she started, had a nice water tail, the previous owner said he replaced the water pump and changed lower oil at the end of last season. Seemed to run very strong, I was able to check compression on the top 3 cylinders (couldn't get the bottom spark plug out as the case was in the way!) and they were all spot on 120 psi. The ignition board (cant remember exactly what it is called, has about 8 wires running out of it) was recently replaced because it cracked, apparently this is a common problem? Ill probably have a mechanic give it a once over once I get it off the current boat, just to make sure everything is in decent shape. Is it hard to change the oil? Id love to learn how to fog and change the oil for winterizing to save on some coin. Thanks again!

Mike

---

Mike, just to be clear this engine (1985 4 cylinder Mercury) is an old school two stroke. No engine oil changing, should be a 50:1 pre-mix of good quality TCW-3 two stroke oil with the fuel in the 6 gallon tank.

The only oil change is to drain and replace the lower unit oil once a year. I'd recommend getting the Mercury pump that fits in their gear oil container. You screw the outlet hose into the lower gear case connection (where the drain plug screws in, located on the front lower side of the gear case "bullet") and pump until the gear oil starts coming out of the upper gear case vent. (The vent screw is further up on the side of the gear case, I think I remember it being just above the cavitation plate.) Make sure the gaskets for both plugs are in good condition when you put the plugs back in to keep water out. (Taking care of the "little" boat was my job from roughly age 13 on... if I took care of it there was always gas in the tank. I miss those days!)

Mercury made the inline 4 design in one shape or form for roughly 60 years, ours was a 1973 that we picked up in 1974. My dad sold it to a high school kid a couple of years ago and as far as I know, it's still going strong. They run great and are very smooth (for a two stroke) because of the 4 cylinder design. If you want to get to that lower spark plug, I believe the lower cowling has a couple of screws accessed from the bottom that will let you drop that to get clearance.

If you search for Chilton's manuals you may have some luck online finding a service manual. Good luck!